Method for producing resorcin/formaldehyde resin

Abstract

A method for producing a resorcin/formaldehyde resin comprising subjecting a salts-containing aqueous solution, resorcin, formaldehydes and aliphatic ketone having 3 to 6 carbon atoms to a polymerization reaction in the presence of an acidic catalyst, separating the reaction liquid after reaction between an aqueous phase and an organic phase, and obtaining a resorcin/formaldehyde resin from the organic phase, wherein the aqueous phase recovered by separating is distilled to adjust the aliphatic ketone content to 0.3 wt % or less and the alcohol content to 0.1 wt % or less, and the aqueous phase having a salts concentration adjusted to 35 to 45 wt % is used as said salts-containing aqueous solution.

Dependencies are inferred from the claim text.